Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Estimated association between reported number of doses and number of SIAs experienced, based on NP-AFP data between January 2010 and July 2015. From left to right, estimates are from models 1, 2, and 3 detailed in Section 2. Note some countries are excluded from analysis of under-immunized or zero-dose fraction analyses due to insufficient cases.
